The present invention relates to specific photochromic h-annellated benzo[f]chromene derivatives and their use in synthetic resins of all types, especially for ophthalmic applications. In particular, the present invention relates to photochromic compounds derived from benzo[f]chromenes, which in their open form have particularly long-wave absorption maxima making it possible to achieve violet to blue tints if used in phototropic glasses.
Various classes of dyes that reversibly change their color when irradiated with light of certain wavelengths, particularly sunlight, are known in the art. This is due to the fact that these dye molecules change into an excited colored state when supplied with energy in the form of light. When the energy supply is interrupted, they leave this state again and return to their colorless or at least hardly colored normal state. These photochromic dyes include, for instance, the naphthopyrans, which have already been described in the prior art with various substituents.
Pyrans, especially naphthopyrans and larger ring systems derived therefrom are photochromic compounds that even today are the subject of intensive investigations. Although a patent application was filed for them as early as 1966 (U.S. Pat. No. 3,567,605), it was not until the nineties that compounds that appeared suitable for use in eyeglasses were developed.
On the one hand, the prior art dyes frequently do not have sufficiently long-wave absorption in the excited or in the unexcited state. This causes problems also in combinations with other photochromic dyes. On the other hand, they are also often excessively temperature sensitive with respect to darkening and brightening is simultaneously too slow. In addition, the described dyes have an insufficiently long service life. Consequently, this type of sunglasses is not sufficiently durable. The latter is noticeable in their rapidly deteriorating performance and/or strong yellowing.
3H-naphthopyrans derived from 2-naphthols and their higher analog derivatives derived therefrom by annellation are a group of photochromic dyes whose longest-wave absorption maximum in the excited form is primarily in the spectral range of 420 nm to 500 nm. As a result they give a yellow, orange or red color impression (see U.S. Pat. No. 5,869,658 and U.S. Pat. No. 6,022,495). For neutrally darkening phototropic glasses, however, powerful violet to blue photochromic dyes are required. Violet to blue photochromic dyes that are currently available in the prior art stem from the class of the spiroxazines, fulgides or 2H-naphtho[1,2-b]pyrans. Spiroxazine dyes, however, are typically disadvantageous with respect to their high-temperature performance, while fulgide dyes do not have satisfactory properties for use in sunglasses regarding their service life and 2H-naphtho[1,2-b]pyrans regarding their brightening rate.
Thus, the object of the present invention is to provide novel photochromic dyes with improved properties compared to the compounds described in the prior art. Compared to comparable prior art compounds, the photochromic compounds are to be distinguished especially by longer-wave absorption in the excited state and at the same time are to exhibit good kinetic and service life properties, i.e., faster brightening rates and good behavior in the durability test.
This object is attained by the subjects characterized in the claims.
Specifically provided are photochromic h-annellated benzo[f]chromenes having the general formula (I): 
where
n and m independently represent 0, 1 or 2,
the radicals R1, R2, R3 and R4 each independently represent a substituent selected from
the group xcex1 consisting of a hydrogen atom, a (C1-C6) alkyl radical, a (C3-C7) cycloalkyl radical, which can have one or more heteroatoms, a (C1-C6) alkoxy radical, a hydroxy group, a trifluoromethyl group, bromine, chlorine and fluorine; the group xcex2 consisting of an unsubstituted, monosubstituted or disubstituted phenyl, phenoxy, benzyl, benzyloxy, naphthyl or naphthoxy radical, wherein the substituents may be selected from the group xcex1 and phenyl;
the group "khgr" wherein the radicals R1 and R2 or R3 and R4 each form an xe2x80x94Axe2x80x94(CH2)kxe2x80x94Bxe2x80x94 group bound to the aromatic ring where k=1 or 2, wherein A and B independently are selected from oxygen, sulfur, CH2, C(CH3)2 or C(C6H5)2, and wherein a benzo ring may in turn be annellated to said xe2x80x94Axe2x80x94(CH2)kxe2x80x94Bxe2x80x94 group;
the group xcex4 consisting of an unsubstituted, monosubstituted or disubstituted amino group, wherein the amine substituents may be selected from a (C1-C6) alkyl radical, a (C3-C7) cycloalkyl radical, a phenyl or benzyl radical unsubstituted or substituted with one or more substituents from the group xcex1, an N-morpholine group, an N-thiomorpholine group, an N-piperidine group, an N-azacycloheptane group, an N-piperazine group, an N-(Nxe2x80x2-(C1-C6-alkyl)piperazine group, an N-pyrrolidine group, an N-imidazolidine group, an N-pyrazolidine group, an N-aziridine group, an N-azetidine group, an N-indoline group, an N-carbazole group, an N-phenothiazine group, an N-phenazine group, an N-phenoxazine group, an N-tetrahydroquinoline group, and an N-tetrahydroisoquinoline group,
the group xcex5, wherein the radicals R1 and R2, i.e., R1/R2, or R3 and R4, i.e., R3/R4, respectively, together form a xe2x80x94Dxe2x80x94(CH2)kxe2x80x94Exe2x80x94 group bound to the benzo ring where k=1 or 2, wherein independently D is selected from N(CH3) or N(C6H5) and E from oxygen, sulfur, CH2, C(CH3)2, C(C6H5)2, N(CH3) or N(C6H5), and wherein a benzo ring may in turn be annellated to this xe2x80x94Dxe2x80x94(CH2)kxe2x80x94Exe2x80x94 group, or
the group xcfx86 wherein the radicals R1 and R2 or R3 and R4, respectively, form a julolidinyl unit together with the benzene ring to which they are bound,
provided that within the radicals R1, R2, R3 and R4 or within R1/R2 and R3/R4 at least one is selected from the aforementioned groups xcex4, xcex5 and xcfx86, i.e., at least one of the radicals R1, R2, R3 and R4 or R1/R2 and R3/R4 is an electron-donating substituent from the class of the nitrogen donor substituents;
the radicals R5, R6, R7 and R8, respectively, independently are selected from the group xcex1 and phenyl, or the radicals R5 and R6 together with the radical R3 of the directly adjacent benzo ring form an unsubstituted, monosubstituted or disubstituted benzo or pyrido ring annellated thereto, whose substituents may be selected from the group xcex1 and phenyl, or, if m or n is 2, the directly adjacent radicals R5 and R6 of two adjacent CR5R6 units or the directly adjacent radicals R7 and R8 of two adjacent CR7R8 units together form an annellated, unsubstituted, monosubstituted or disubstituted benzo or pyrido ring whose substituents may be selected from the group xcex1 and phenyl, or the radicals R5 and R6 and/or the radicals R7 and R8 together represent a (C3-C7) cycloalkyl radical, which can have one or more heteroatoms, such as, for instance, oxygen, nitrogen or sulfur, wherein a benzo ring may be annellated to this cycloalkyl radical;
X is selected from O, S, CR9R10 or NR11, wherein the radical R11 can be hydrogen, cyano, (C1-C6) alkyl, (C3-C7) cycloalkyl or phenyl, and the radicals R9 and R10 independently are selected from the group xcex1 and phenyl, or the radicals R9 and R10 together represent a (C3-C7) cycloalkyl radical, which can have one or more heteroatoms, or, if X is CR9R10, the radicals R9 and R10 together with the radicals R5 and R6 or R7 and R8 of a directly adjacent CR5R6 unit or CR7R8 unit can also stand for an unsubstituted, monosubstituted or disubstituted benzo or pyrido ring annellated to the Xxe2x80x94C(R5R6) or Xxe2x80x94C(R7R8) bond whose substituents may be selected from the group xcex1 and phenyl;
B and Bxe2x80x2 independently are selected from one of the following groups a), b), c) or d), wherein they
a) are monosubstituted, disubstituted or trisubstituted aryl radicals wherein the aryl radical is phenyl or naphthyl;
b) are unsubstituted, monosubstituted and disubstituted heteroaryl radicals, wherein the heteroaryl radical is pyridyl, furanyl, benzofuran-2-yl, benzofuran-3-yl, thienyl, benzothieno-2-yl, benzothieno-3-yl, or julolidinyl; wherein the substituents of the aryl or the heteroaryl radicals in a) and b) are those selected from the groups xcex1, xcex2 or xcex4 or two directly adjacent substituents together can form a xe2x80x94Dxe2x80x94(CH2)kxe2x80x94Exe2x80x94 group bound to the benzo ring as defined above, i.e., k stands for 1 or 2 and independently D stands for xe2x80x94N(CH3) or xe2x80x94N(C6H5) and E for oxygen, sulfur, CH2, C(CH3)2, C(C6H5)2, xe2x80x94N(CH3) or xe2x80x94N(C6H5), and a benzo ring can in turn be annellated to this xe2x80x94Dxe2x80x94(CH2)kxe2x80x94Exe2x80x94 group;
c) are structural units having the following formulas (V) and (W): 
where
Y and Z independently are O, S, CH, CH2 or NR11, wherein the radical R11 is as defined above, the radicals R12 and R13 independently represent hydrogen and/or a (C1-C6) alkyl radical and the radical R14 is a substituent from the group xcex1, wherein p is 1, 2, or 3, provided that, if Y in formula (V) is NR11, Z is carbon, or
d) B and Bxe2x80x2 together form an unsubstituted, monosubstituted or disubstituted fluorene-9-ylidene radical or a saturated hydrocarbon radical, which is C3-C12 spiro-monocyclic, C7-C12 spiro-bicyclic and/or C7-C12 spiro-tricyclic wherein the fluorene substituents are selected from the group xcex1.
According to the present invention, through h-annellation of benzo[f]chromene systems, compounds are provided whose photochromic properties have advantages compared to the compounds known in the prior art. In particular, the compounds according to the invention have especially long-wave absorption maxima in the open (colored) form, so that for the first time violet to blue tints can be obtained for benzo[f]chromene systems (nomenclature according to IUPAC; other name: 3H-naphtho[1,2-b]pyrans). At the same time, the inventive photochromic h-annellated benzo[f]chromene derivatives have comparable kinetic and service life properties compared to corresponding compounds from the prior art, i.e., rapid brightening rate and good behavior in the durability test.